DTC P1574 ASCD VEHICLE SPEED SENSOR
EC-1321
[VK45DE]
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DTC P1574 ASCD VEHICLE SPEED SENSORPFP:31036
Component DescriptionNBS005N6
The ECM receives two vehicle speed sensor signals via CAN communication line. One is sent from “unified
meter and A/C amp.”, and the other is from TCM (Transmission control module). The ECM uses these signals
for ASCD control. Refer to EC-746, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for ASCD functions.
On Board Diagnosis LogicNBS005N7
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:
If DTC P1574 is displayed with DTC U1000, U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-886, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
If DTC P1574 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010.
Refer to EC-889, "
DTC U1010 CAN COMMUNICATION" .
If DTC P1574 is displayed with DTC P0500, first perform the trouble diagnosis for DTC P0500.
Refer to EC-1200, "
DTC P0500 VSS"
If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-1215, "
DTC P0605 ECM"
DTC Confirmation ProcedureNBS005N8
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Step 3 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Start engine (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Drive the vehicle at more than 40 km/h (25 MPH).
4. If DTC is detected, go to EC-1322, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P1574
1574ASCD vehicle speed
sensorECM detects a difference between two vehicle
speed signals is out of the specified range.
Harness or connectors
(The CAN communication line is open or
shorted.)
Unified meter and A/C amp.
ABS actuator and electric unit (control unit)
Wheel sensor
TCM
ECM
SEF058Y
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GENERAL INFORMATION
A GENERAL INFORMATION
CONTENTS
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SECTION GI
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GENERAL INFORMATION
PRECAUTIONS .......................................................... 3
Description ............................................................... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 3
Precautions for NVIS/IVIS (NISSAN/INFINITI
VEHICLE IMMOBILIZER SYSTEM - NATS) (If
Equipped) ................................................................. 3
Precautions Necessary for Steering Wheel Rotation
After Battery Disconnect .......................................... 4
OPERATION PROCEDURE ................................. 4
Precautions for Procedures without Cowl Top Cover ..... 4
General Precautions ................................................ 4
Precautions for Three Way Catalyst ......................... 6
Precautions for Fuel (Unleaded Premium Gasoline
Recommended) ...................................................
..... 6
Precautions for Fuel (Unleaded Premium Gasoline
Required) ................................................................. 6
Precautions for Multiport Fuel Injection System or
Engine Control System ............................................ 7
Precautions for Hoses .............................................. 7
HOSE REMOVAL AND INSTALLATION ............... 7
HOSE CLAMPING ................................................ 7
Precautions for Engine Oils ...................................... 8
HEALTH PROTECTION PRECAUTIONS ............. 8
Precautions for Air Conditioning ............................... 8
HOW TO USE THIS MANUAL ................................... 9
Description ............................................................... 9
Terms ....................................................................... 9
Units ......................................................................... 9
Contents ................................................................... 9
Relation between Illustrations and Descriptions .... 10
Components ............................................................ 11
SYMBOLS ........................................................
.... 11
How to Follow Trouble Diagnoses .......................... 12
DESCRIPTION .................................................... 12
HOW TO FOLLOW TEST GROUPS IN TROU-
BLE DIAGNOSES ............................................... 12
HARNESS WIRE COLOR AND CONNECTOR
NUMBER INDICATION ....................................... 13KEY TO SYMBOLS SIGNIFYING MEASURE-
MENTS OR PROCEDURES ............................... 14
How to Read Wiring Diagrams ............................... 16
CONNECTOR SYMBOLS ................................... 16
SAMPLE/WIRING DIAGRAM - EXAMPL - .......... 17
DESCRIPTION .................................................... 18
Abbreviations .......................................................... 24
SERVICE INFORMATION FOR ELECTRICAL INCI-
DENT ......................................................................... 25
How to Check Terminal ........................................... 25
CONNECTOR AND TERMINAL PIN KIT ............ 25
HOW TO PROBE CONNECTORS ...................... 25
How to Perform Efficient Diagnosis for an Electrical
Incident ................................................................... 28
WORK FLOW ...................................................... 28
INCIDENT SIMULATION TESTS ........................ 28
CIRCUIT INSPECTION ....................................
... 31
Control Units and Electrical Parts ........................... 36
PRECAUTIONS .................................................. 36
CONSULT-II CHECKING SYSTEM .......................... 38
Description .............................................................. 38
Function and System Application ........................... 38
Nickel Metal Hydride Battery Replacement ............ 39
Checking Equipment .............................................. 39
CONSULT-II Start Procedure .................................. 39
CONSULT-II Data Link Connector (DLC) Circuit .... 40
INSPECTION PROCEDURE .............................. 40
CIRCUIT DIAGRAM ............................................ 41
LIFTING POINT ......................................................... 42
Special Service Tools ............................................. 42
Garage Jack and Safety Stand and 2-Pole Lift ....... 42
Board-On Lift .......................................................... 43
TOW TRUCK TOWING ............................................. 44
Tow Truck Towing ................................................... 44
2WD MODELS .................................................... 44
AWD MODELS .................................................... 45
Vehicle Recovery (Freeing a Stuck Vehicle) ........... 45
FRONT ................................................................ 45
REAR .................................................................. 45
AUTOMATIC TRANSMISSION ........................... 46
GI-2Revision: 2006 January2006 M35/M45 TIGHTENING TORQUE OF STANDARD BOLTS .... 47
Tightening Torque Table ......................................... 47
RECOMMENDED CHEMICAL PRODUCTS AND
SEALANTS ............................................................... 48
Recommended Chemical Products and Sealants ... 48
IDENTIFICATION INFORMATION ............................ 49
Model Variation ....................................................... 49
IDENTIFICATION NUMBER ................................ 50IDENTIFICATION PLATE .................................... 51
ENGINE SERIAL NUMBER ................................. 51
AUTOMATIC TRANSMISSION NUMBER ........... 51
Dimensions ............................................................. 52
Wheels & Tires ........................................................ 52
TERMINOLOGY ........................................................ 53
SAE J1930 Terminology List ................................... 53
PRECAUTIONS
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Before jacking up the vehicle, apply wheel chocks or other tire
blocks to the wheels to prevent the vehicle from moving. After
jacking up the vehicle, support the vehicle weight with safety
stands at the points designated for proper lifting before working
on the vehicle.
These operations should be done on a level surface.
When removing a heavy component such as the engine or tran-
saxle/transmission, be careful not to lose your balance and drop
them. Also, do not allow them to strike adjacent parts, especially
the brake tubes and master cylinder.
Before starting repairs which do not require battery power:
Turn off ignition switch.
Disconnect the negative battery terminal.
If the battery terminals are disconnected, recorded memory of
radio and each control unit is erased.
Battery posts, terminals and related accessories contain lead
and lead compounds. Wash hands after handling.
To prevent serious burns:
Avoid contact with hot metal parts.
Do not remove the radiator cap when the engine is hot.
Dispose of or recycle drained oil or the solvent used for cleaning
parts in an appropriate manner.
Do not attempt to top off the fuel tank after the fuel pump nozzle
shuts off automatically.
Continued refueling may cause fuel overflow, resulting in fuel
spray and possibly a fire.
Clean all disassembled parts in the designated liquid or solvent
prior to inspection or assembly.
Replace oil seals, gaskets, packings, O-rings, locking washers, cotter pins, self-locking nuts, etc. with new
ones.
Replace inner and outer races of tapered roller bearings and needle bearings as a set.
Arrange the disassembled parts in accordance with their assembled locations and sequence.
Do not touch the terminals of electrical components which use microcomputers (such as ECM).
Static electricity may damage internal electronic components.
After disconnecting vacuum or air hoses, attach a tag to indicate the proper connection.
Use only the fluids and lubricants specified in this manual.
Use approved bonding agent, sealants or their equivalents when required.
Use hand tools, power tools (disassembly only) and recom-
mended special tools where specified for safe and efficient ser-
vice repairs.
When repairing the fuel, oil, water, vacuum or exhaust systems,
check all affected lines for leaks.
SGI231
SEF289H
SGI233
PBIC0190E
HOW TO USE THIS MANUAL
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HOW TO USE THIS MANUALPFP:00008
Description NAS0007G
This volume explains “Removal, Disassembly, Installation, Inspection and Adjustment” and “Trouble Diag-
noses”.
Te r m sNAS0007H
The captions WARN ING and CAUTION warn you of steps that must be followed to prevent personal
injury and/or damage to some part of the vehicle.
WARN ING indicates the possibility of personal injury if instructions are not followed.
CAUTION indicates the possibility of component damage if instructions are not followed.
BOLD TYPED STATEMENTS except WARNING and CAUTION give you helpful information.
Standard value:Tolerance at inspection and adjustment.
Limit value:The maximum or minimum limit value that should not be exceeded at inspection and adjust-
ment.
UnitsNAS0007I
The UNITS given in this manual are primarily expressed as the SI UNIT (International System of Unit),
and alternatively expressed in the metric system and in the yard/pound system.
Also with regard to tightening torque of bolts and nuts, there are descriptions both about range and about
the standard tightening torque.
“Example”
Range
Standard
ContentsNAS0007J
ALPHABETICAL INDEX is provided at the end of this manual so that you can rapidly find the item and
page you are searching for.
A QUICK REFERENCE INDEX, a black tab (e.g. ) is provided on the first page. You can quickly find
the first page of each section by matching it to the section's black tab.
THE CONTENTS are listed on the first page of each section.
THE TITLE is indicated on the upper portion of each page and shows the part or system.
THE PAGE NUMBER of each section consists of two or three letters which designate the particular sec-
tion and a number (e.g. “BR-5”).
THE SMALL ILLUSTRATIONS show the important steps such as inspection, use of special tools, knacks
of work and hidden or tricky steps which are not shown in the previous large illustrations.
Assembly, inspection and adjustment procedures for the complicated units such as the automatic tran-
saxle or transmission, etc. are presented in a step-by-step format where necessary. Outer Socket Lock Nut : 59 - 78 Nꞏm (6.0 - 8.0 kg-m, 43 - 58 ft-lb)
Drive Shaft Installation Bolt : 44.3 Nꞏm (4.5 kg-m, 33 ft-lb)
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HOW TO USE THIS MANUAL
Revision: 2006 January2006 M35/M45
AbbreviationsNAS0007O
The following ABBREVIATIONS are used:
ABBREVIATION DESCRIPTION
A/C Air Conditioner
A/T Automatic Transaxle/Transmission
ATF Automatic Transmission Fluid
D
1Drive range 1st gear
D
2Drive range 2nd gear
D
3Drive range 3rd gear
D
4Drive range 4th gear
FR, RR Front, Rear
LH, RH Left-Hand, Right-Hand
M/T Manual Transaxle/Transmission
OD Overdrive
P/S Power Steering
SAE Society of Automotive Engineers, Inc.
SDS Service Data and Specifications
SST Special Service Tools
2WD 2-Wheel Drive
2
22nd range 2nd gear
2
12nd range 1st gear
1
21st range 2nd gear
1
11st range 1st gear
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TOW TRUCK TOWING
Revision: 2006 January2006 M35/M45
TOW TRUCK TOWINGPFP:00000
Tow Truck TowingNAS00081
CAUTION:
All applicable state or Provincial (in Canada) laws and local laws regarding the towing operation
must be obeyed.
It is necessary to use proper towing equipment to avoid possible damage to the vehicle during
towing operation. Towing is in accordance with Towing Procedure Manual at dealer.
Always attach safety chains before towing.
When towing, make sure that the transmission, steering system and powertrain are in good order.
If any unit is damaged, dollies must be used.
Never tow an automatic transmission model from the rear (that is backward) with four wheels on
the ground. This may cause serious and expensive damage to the transmission.
2WD MODELS
INFINITI recommends that vehicle be towed with the driving (rear) wheels off the ground or that a dolly be
used as illustrated.
CAUTION:
Never tow automatic transmission models with the rear wheels on the ground or four wheels on
the ground (forward or backward), as this may cause serious and expensive damage to the trans-
mission.
If it is necessary to tow the vehicle with the front wheels raised, always use towing dollies under
the rear wheels.
When towing rear wheel drive models with the front wheels on the ground or on towing dollies:
–Turn the ignition key to the OFF position, and secure the steering wheel in a straight ahead posi-
tion with a rope or similar device.Never secure the steering wheel by turning the ignition key to the
LOCK position. This may damage the steering lock mechanism.
–Move the selector lever to the N (Neutral) position.
When the battery of vehicle equipped with the Intelligent Key system is discharged, your vehicle
should be towed with the front wheels on towing dollies or place the vehicle on a flat bed truck.
If the speed or distance must necessarily be greater, remove the propeller shaft before towing to prevent dam-
age to the transmission.
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TOW TRUCK TOWING
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AUTOMATIC TRANSMISSION
To tow a vehicle equipped with an automatic transmission, an appropriate vehicle dolly MUST be placed
under the towed vehicle's drive wheels. Always follow the dolly manufacture's recommendations when using
their product.
If the vehicle is stuck in sand, snow, mud, etc., use the following procedure:
1. Turn off the Vehicle Dynamic Control System.
2. Make sure the area in front and behind the vehicle is clear of obstructions.
3. Turn the steering wheel right and left to clear an area around the front tires.
4. Slowly rock the vehicle forward and backward.
Shift back and forth between R (reverse) and D (drive).
Apply the accelerator as little as possible to maintain the rocking motion.
Release the accelerator pedal before shifting between R and D.
Do not spin the tires above 35 mph (55 km/h).
5. If the vehicle can not be freed after a few tries, contact a professional towing service to remove the vehi-
cle.